Test of gel, pills to prevent HIV fails in real-life study

African women who were testing a gel or a pill to protect them from the AIDS virus weren’t able to use either consistently enough to tell if they worked, researchers reported Monday.

The news is a disappointment to the field, especially since an earlier study suggested the gel could really lower the infection rate.

“The bottom line is the women were not using the products,” Jeanne Marrazzo of the University of Washington in Seattle told a news conference. And the women who were the least likely to use the pills or gel as directed were those most at risk – young women under 25, who weren’t married and may have had multiple sex partners.

The findings are “disappointing,” Marrazzo told a meeting of AIDS researchers in Atlanta called the Conference on Retroviruses and Opportunistic Infections.

Researchers have been trying for years to find good ways that women, especially, can use to protect themselves from the human immunodeficiency virus that causes AIDS. More than 60 percent of adults newly diagnosed with HIV in Africa -- where the epidemic is worst -- are women infected by husbands and other male sex partners.

Studies have shown that microbicide gels or creams can work -- at the last AIDS conference in Vienna in 2010, researchers reported on one that reduced a woman’s risk of infection by 39 percent. And other studies have shown that taking a daily AIDS drug in pill form can also protect people at high risk -- such as the spouses and partners of infected people. The trials have worked well in some countries, but not others. Experts fear inconsistent use may be one problem.

The trial reported Monday confirms these fears.

Marrazzo and colleagues tested three different approaches in more than 5,000 women in Uganda, South Africa and Zimbabwe. They tried two pills containing HIV medicines and a vaginal gel. After the study started in 2009, 312 of the 5,029 women became infected – an infection rate of 5.7 percent. That was almost double the rate the researchers had expected.

“The women who were most likely to take the drugs were women who were older than 25 and who were married,” Marrazzo said. They were probably the women at the lowest risk, but because so few women used the gel or took the pills as directed, the researchers couldn’t really tell anything about how well the drugs worked.

"No intervention is going to be effective if it's not used,” Dr. Zvavahera Mike Chirenje of the University of Zimbabwe in Harare, who helped direct the study, said in a statement.

Researchers are looking for approaches that won’t require people to remember to take a pill or use a gel every single day. One team has begun a trial of a device called a vaginal ring impregnated with dapivirine, a drug used to treat people with HIV. Researchers will enroll 3,500 women in the two-year study to be conducted in Africa. Women could insert the ring and not think about it for as long as a month at a time.

Products that are long-acting, such as the dapivirine vaginal ring … and that women use for a month at a time, may be more suitable for this vulnerable population,” said Sharon Hillier of the University of Pittsburgh School of Medicine, who is helping to lead that trial.

The AIDS virus infects 34 million people globally and has killed 25 million more, according to the United Nations. Every year, more than 2 million more people are infected. There’s no vaccine and no cure, although cocktails of strong drugs can keep patients healthy, and low doses of certain drugs can help prevent infection.